The capacity of an air conditioning unit is described in British thermal units rather than wattage or amperage. Those who wish to determine the cost of running a 5,000 BTU air cooler must know the amperage rating, or be prepared to convert the amount of energy used into wattage. Find the wattage to find out how much it costs to run the cooling unit for an hour, day, week, month or year.
2. Calculating the Wattage from the Amperes.
Multiply the five-amp figure by the number of volts on the outlet, in general this figure will be 110. For instance, 5 x 110=550 watts. This is the way to calculate the kilowatt hours.
3. Ask the energy company how much they charge per kilowatt hour. The average charge is around twelve cents.
4. Work Out How Much It Costs to Run the Air Con for 24 Hours.
Use the formula of watts x hours of usage divided by one thousand x cost per kilowatt hour = running costs. (Divide by one thousand to convert the watt-hours to kilowatt-hours).
For instance, the mathematical formula used looks similar to this: 550 x 24 divided by 1,000 x $0.12. So, running a five amp, 5000 Btu air conditioning unit for twenty four hours costs around $1.60.
5. Divide the daily cost by 24 to get the hourly running cost. For instance, $1.60 divided by twenty four equals six, hence it costs six cents an hour to run the unit.
6. Get the weekly running costs by multiplying the cost per day, in this case multiply $1.60 by seven. Work out the monthly running costs by multiplying the weekly running costs by four, in this case multiply $1.60 by four, which equals $11.20. Calculate the annual running cost by multiplying the monthly running costs by twelve. On average it costs $585 a year to run a 5,000 BTU air conditioner.